The invention relates generally to an apparatus for electrically stunning animals to be slaughtered, in particular pigs. More specifically, the invention relates to apparatus comprising two endless conveyors, which are operable to run parallel to each other and at a synchronized rate and are positioned to form a substantially V-shaped passageway therebetween, an a pair of electrodes or sets of electrodes, being adapted to engage the head of the animals and to extend downwardly into said V-shaped passageway at a distance spaced apart from each other in line with the direction of movement of said conveyors. The electrodes pivot in the direction of movement from their initial position, and pivot about horizontal shafts arranged above said conveyors when counteracting spring pressure is overcome as an animal being transported by the conveyors is pushed against the electrodes.
Typical of such conveyor-type apparatus is that disclosed in application Ser. No. 905,371, which is based upon Dutch patent application No. 77.05519 laid open to public inspection.
In electrically stunning animals to be slaughtered, in particular pigs, it is of utmost importance that a proper contact is attained between the animals to be stunned and the electrodes. The jolt of current used to stun the animal should be short and intense.
In case of insufficient stunning muscular contractions may cause internal bleeding and bone breakage which distract from the value of the meat.
An irregular contact which is insufficient will cause a stress condition in the animal, whereby the pH of the meat will change which, in turn, reduces the quality and value of the meat. A short jolt of high current is necessary and should be applied as soon as a proper contact between the electrodes and the animal is achieved.
In an apparatus for electrically stunning animals to be slaughtered, a high production level, for example on the order of 300 to 600 pigs per hour, is desired.
However, the animals to be stunned are of different sizes which will result in different heights of animals being transported between the V-shaped conveyors. On the other hand, thereto the size of the heads of the animals will differ in a lesser degree. Also, some animals will try to escape from the electrodes by moving their head downwardly or to the side.
A feature of the present invention resides in improving the apparatus disclosed in my prior application in such a way that a good contact is achieved at the proper place under all circumstances.